There are the following reports on preparations containing an insulin sensitizer such as a thiazolidinedione and the like and an active ingredient (except insulin sensitizers).    1) A pharmaceutical agent containing an insulin sensitizer in combination with at least one member from an α-glucosidase inhibitor, an aldose reductase inhibitor, a biguanide, a statin compound, a squalene synthetase inhibitor, a fibrate compound, an LDL catabolism enhancer and an angiotensin converting enzyme inhibitor (EP749751A).    2) A pharmaceutical composition containing an insulin sensitizer, a biguanide antihyperglycaemic agent and a pharmaceutically acceptable carrier (WO98/57634, US2002/0004515A).    3) A pharmaceutical composition containing a thiazolidinedione, metformin hydrochloride and a pharmaceutically acceptable carrier, wherein the thiazolidinedione is formulated upon the surface of metformin hydrochloride (WO01/35940).    4) A pharmaceutical composition containing a thiazolidinedione, metformin hydrochloride and a pharmaceutically acceptable carrier, wherein the thiazolidinedione and metformin hydrochloride are respectively dispersed in pharmaceutically acceptable carriers of their own (WO01/35941).    5) A core formulation comprising (a) a first layer containing pioglitazone hydrochloride or a pharmaceutically acceptable salt thereof as an active ingredient, and (b) a core containing a biguanide as an active ingredient, wherein at least a portion of the core is enclosed by said first layer (WO01/82875).    6) a composition for treating diabetes, which contains an insulin sensitizer and an antidiabetic agent (U.S. Pat. No. 6,153,632, WO02/04024).